Interior components in an automobile are often produced as a series having different specifications, where a high specification automobile uses an interior part with a high specification, and a low specification vehicle uses an interior part having a low specification. One example of this is where a stitch line is applied to components of a series with a high specification in order to give a ‘hand crafted’ appearance to those components. Such a stitch line is usually intended to appear as if it is required for the manufacture of the part, but in fact it is usually merely decorative.
In order to produce a hand stitched appearance, conventionally, a molded substrate is produced which defines the shape of the required component, for example an instrument panel or console, or a door trim. A cover material, for example poly vinyl chloride (PVC) or thermoplastic polyolefin (TPO) is cut into parts of appropriate shapes according to a pattern in a similar manner to the method used when making a garment. The parts are then sewn together to form the shape required to clad the molded substrate. The completed cover is then placed over the substrate and bonded in place. A foamed material may be used between the substrate and the cover in order to achieve a soft feel for the component and this foamed material which may act as a bonding agent.
Disadvantages of this conventional process are that the process is very labor intensive, and thus it is impractical to produce parts with such an appearance in large volumes. Furthermore, the process involves stretching the skin after the parts have been sewn together, which may create a weakness along the stitch line.
Therefore, there is a need in the automotive interior industry to produce in large quantities, decorative cover that have the appearance that the part has been handcrafted.